• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1824-1827
• /
• 1997

Majority of industrial robots are controlled by a simple joint servo control of joint actuators. In this type of control, the performance of control is influenced greatly by the joint interaction torques including Coriolis and centrifugal forces, which act as disturbance torques to the control system. As the speed of the robot increases, the effect of this disturbance torque increases, and makes the high speed-high precision control more difficult to achieve. In this paper, the joint disturbance torque of robots is analyzed. The joint disturbance torque is defined using the coefficients of dynamic equation of motion, and for the case of a 2DOF planar robot, the conditions for the maximum joint disturbance torques are identified, and the effect of link parameters and joint variables on the joint disturbance torque are examined. Then, a solutioin to the optimal path placement problem is proposed that minimizes the joint disturbance torque are examined. then, a solution to the optimal path placement problem is proposed that minimizes the joint disturbance torque during a straight line motion. the proposed method is illustrated using computer simulation. the proposed solution method cna be applied to the class of robots that are controlled by independent joint sevo control, which includes the vast majority of industrial robots. By minimizing the joint disturbacne torque during the motion, the simple joint servo controlled robot can move with improved path tracking accuracy at high speed.

• Journal of Korea Multimedia Society
• /
• v.23 no.10
• /
• pp.1318-1330
• /
• 2020

The purpose of this study is to identify the effect of the innovation characteristics that AI Elderly Care Robots have on elderly consumers and to verify the acceptance or mediated resistance by the elderly of the innovation characteristics. Research was conducted throughout this study of the characteristics of the elderly so that the study results could contribute to the improvement of the quality and manufacture of AI Elderly Care Robots by lowering the psychological resistance of the elderly. Survey questions were answered by senior citizens aged 65 and older. The SPSS25 and AMOS22 programs were used for analysis. The analysis confirmed that innovation resistance has a significant mediated effect on the characteristics of elderly consumers and their willingness to accept the innovation characteristics of the AI Elderly Care Robots. Through this study, Ram's innovation resistance model has been verified empirically and it is estimated that by considering the specificities of elderly consumers and using the information to contribute to the development and modification of AI Elderly Care Robots will increase the willingness of the elderly to accept the innovation characteristics of the AI Elderly Care Robots.

• Nuclear Engineering and Technology
• /
• v.49 no.7
• /
• pp.1414-1422
• /
• 2017

Remote response technology has advanced to the extent that a robot system, if properly designed and deployed, may greatly help respond to beyond-design-basis accidents at nuclear power plants. Particularly in the aftermath of the Fukushima accident, there is increasing interest in developing disaster robots that can be deployed in lieu of a human operator to the field to perform mitigating actions in the harsh environment caused by extreme natural hazards. The nuclear robotics team of the Korea Atomic Energy Research Institute (KAERI) is also endeavoring to construct disaster robots and, first of all, is interested in finding out to what extent safety benefits can be achieved by such a disaster robotic system. This paper discusses a new approach based on the probabilistic risk assessment (PRA) technique, which can be used to quantify safety benefits associated with disaster robots, along with a case study for seismic-induced station blackout condition. The results indicate that to avoid core damage in this special case a robot system with reliability > 0.65 is needed because otherwise core damage is inevitable. Therefore, considerable efforts are needed to improve the reliability of disaster robots, because without assurance of high reliability, remote response techniques will not be practically used.

• The Journal of Korea Robotics Society
• /
• v.13 no.3
• /
• pp.151-156
• /
• 2018

Military robots are expected to play an important role in the future battlefield, and will be actively engaged in dangerous, repetitive and difficult tasks. During the robots perform the tasks a human operator controls the robots in a supervisory way. The operator recognizes battlefield situations from remote robots through an interface of the operator control center, and controls them. In the meantime, operator workload, controller interface, robot automation level, and task complexity affect robot operability. In order to assess the robot operability, we have developed ROSim (Robot Operational Simulator) incorporating these operational factors. In this paper, we introduce the results of applying ROSim experimentally to the assessment of reconnaissance robot operability in a battle field. This experimental assessment shows three resulting measurements: operational control workload, operational control capability, mission success rate, and discuss its applicability to the defense robot research and development. It is expected that ROSim can contribute to the design of an operator control center and the design analysis of a human-robot team in the defense robot research and development.

• Journal of the Korea Computer Industry Society
• /
• v.5 no.9
• /
• pp.993-1004
• /
• 2004

We propose the method for kinematic and dynamic modeling and Path-tracking of four-wheeled mobile robots with 2 d.o.f having the limited drive-torques. Controllability of wheeled-mobile robots is revealed by using the kinematic model. Instantaneously coincident coordinate system, force/torque propagation and Newton's equilibrium law are used to induce the dynamic model. When drive-torques generated by inverse dynamics exceed the limitation, we make wheeled-mobile robots follow the reference path by modifying the planned reference trajectory with time-scaling. The controller is introduced to compensate for error owing to modeling uncertainty and measurement noise. And simulation results prove that the method proposed by this paper is efficient.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.11
• /
• pp.1353-1360
• /
• 2012

The Jacobian and singularity analysis of parallel robots is necessary to analyze robot motion. The derivations of the Jacobian matrix and singularity configuration are complicated and have no geometrical earning in the velocity form of the Jacobian matrix. In this study, the screw theory is used to derive the Jacobian of parallel robots. The statics form of the Jacobian has a geometrical meaning. In addition, singularity analysis can be performed by using the geometrical values. Furthermore, this study shows that the screw theory is applicable to redundantly actuated robots as well as non-redundant robots.

• The Journal of Korea Robotics Society
• /
• v.10 no.3
• /
• pp.139-145
• /
• 2015

This paper proposed a method of cooperative control of three mobile robots for carrying an object placed on a floor together. Each robot moves to the object independently from its location to a pre-designated location for grasping the object stably. After grasping the common object, the coordination among the robots has been achieved by a master-slave mode. That is, a trajectory planning has been done for the master robot and the distances form the master robot to the two slave robots have been kept constant during the carrying operation. The localization for mobile robots has been implemented using the encoder data and inverse kinematics since the whole system does not have the slippage as much as a single mobile robot. Before the carrying operation, the lifting operations are implemented using the manipulators attached on the top of the mobile robots cooperatively. The real cooperative lifting and carrying operations are implanted to show the feasibility of the master-slave mode control based on the kinematics using the mobile manipulators developed for this research.

• The Journal of Korea Robotics Society
• /
• v.15 no.2
• /
• pp.160-168
• /
• 2020

There exists a popular belief that the elderly are more conservative than the younger people in acceptability of new technology. This study explores whether the generation gap in technology acceptance exists in the case of using telepresence robots, which project the presence and mobility of remote operator, for the universal purpose of social participation rather than for specific applications. Two groups of senior citizens and undergraduate students in their twenties personally experienced the telepresence robots operation and conducted a survey on how they perceived the social participation of a remote operator mediated by telepresence robot and to what extent the remote operator deserve equal rights to be treated as if one really exists in the local environment. The results show that the elderly have higher expectation on the role and functions of telepresence robots, and more favorable in principle for a remote operator to exercise equal rights by operating telepresence robot. It suggests that the stereotypes, the elderly lag behind younger generation in accepting new technology, is unlikely to fit into the telepresence robot market, for the elderly have more favor and support using telepresence robots as an universal avatar for social participation.

• The Journal of Korea Robotics Society
• /
• v.6 no.1
• /
• pp.10-17
• /
• 2011

This paper deals with researching and designing the fastening parts to be used in order to assemble various Teaching Aids Robots (or Hands-on Robots) with originally incompatible parts supplied by different manufacturers. The suggested fastening parts provide the compatibility among Teaching Aids Robots even though the educational robot customers use incompatible parts from different companies. The designed fastening parts are classified into four set groups such as frame set, sliding-bar set, connector set, and set of chuck and rivet/bolt. Each set of the fastening parts reflects the needs collected from the users, and then some portion of new idea has been added to implement the needs. In this paper, the examples of the Teaching Aids Robots which are assembled with both commercial parts and the designed parts are presented in order to evaluate the compatibility and usability of the suggested fastening parts. As a result, both compatibility and usability of the fastening parts suggested in this paper were proved. The designed fastening parts have been distributed to more than 100 elementary schools nationwide.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.10
• /
• pp.151-157
• /
• 2006

As people's living standard is being improved, human works are being replaced by robots. However, because most robots are used in process industry, fixed on the ground, we need to develop human robots that have wide applications. Currently many researches are being conducted on human robots with the object of replacing human works, but because of lack of relevant hardware, such robots are being applied limitedly to very simple tasks. To overcome the limitation, the present study developed a kinematical mechanism and a controller. Based on human kinematics, the shoulders and the arms were composed of master arms with 3 degree of freedom, and we reproduced motions similar to human ones through the characteristics of joint variables and experiment on the trajectory of the end effector.